Preheat the oven to 400F.,Cut the crust off the bread and tear the remaining loaf into 1-inch pieces.,Using your hands, toss with 6 tablespoons olive oil, squeezing the bread with your hands to help it absorb the olive oil.,Toast on a baking sheet 12 to 15 minutes, tossing often, until the croutons are golden brown and crispy on the outside but still a little soft and tender inside.,______,Meanwhile, toast the fennel seeds in a small pan over medium heat 2 to 3 minutes, shaking the pan often, until the seeds release their aroma and turn a light golden brown.,Coarsely grind the seeds with a mortar and pestle or spice grinder.,Heat a large saute pan over high heat for 2 minutes.,Add the remaining 2 tablespoons olive oil and the pancetta.,Saute 1 to 2 minutes, stirring with a wooden spoon.,Turn the heat down to medium, add the rosemary sprig and the chile, and let them sizzle in the pan a minute.,Add the onion, fennel, fennel seeds, and thyme.,Season with 1/4 teaspoon salt and a few grindings of pepper.,Saute about 8 minutes, until the vegetables are lightly caramelized.,Stir in the lemon zest, and add the entire mixture to the croutons.,Return the pan to high heat and pour in the white wine.,Bring the wine to a boil, and reduce by three-quarters.,Add the chicken stock and bring to a boil.,Pour the hot liquid over the croutons and vegetables, and toss well to combine.,Wipe the pan out with paper towels, and return it to the stove over medium heat.,Swirl in 2 tablespoons butter, and when it foams, add the chestnuts.,Saute 4 to 5 minutes, until the chestnuts are golden and sizzling in the butter.,Season with a pinch of salt and pepper, and add to the stuffing.,Stir to combine, and taste for seasoning.,Add the egg and parsley.,Toss well, and put the stuffing in a ceramic baking dish or casserole.,Cover with foil, and bake 40 minutes.,Remove the foil, and top the stuffing with the remaining 2 tablespoons butter, cut into small cubes.,Return the stuffing to the oven, and cook about 20 minutes, until crispy on top.